What are the underlying causes and dynamics of land use conflicts in metropolitan junction areas?A case study of the central Chengdu–Chongqing region in China

Land use conflicts(LUCs),as a spatial manifestation of the conflicts in the human-land relationships,have a profound impact on regional sustainable development.For China’s metropolitan junction areas(MJAs),the existence of“administrative district economies”has made the issue of LUCs more prominent.Based on a case study of the central Chengdu–Chongqing region,we conducted an exploratory spatial data analysis of the evolutionary process of regional LUCs.Furthermore,structural equation modeling was utilized to analyze the dynamic mechanism of LUCs in MJAs,with a particular emphasis on exploring the influences of administrative boundary.The results showed that from 2010 to 2020,LUCs in the central Chengdu–Chongqing region continued to worsen,and the spatial process conflict and spatial structure conflict indices increased by more than 30.0%.The intensification of LUCs in the central Chengdu–Chongqing region from 2010 to 2020 was mainly the result of the deterioration of conflicts in evaluation units with low conflict levels.LUCs in China’s metropolitan areas generally presented a circular gradient distribution,weakening from the core to the periphery,but there were some strong isolated conflict zones in the outer regions.LUCs in China’s MJAs were the result of interactions among multiple factors,e.g.,natural environment,socio-economic development,policy and institutional processes,and administrative boundary effects.Administrative boundary affected the flow of socio-economic elements,changing the supply-and-demand competition of stakeholders for land resources,consequently exerting an indirect influence on LUCs.This study advances the theory of the dynamic mechanism of LUCs,and provides theoretical support for the governance of these conflicts in transboundary areas.

Surface Regional Heat(Cool) Island Effect and Its Diurnal Differences in Arid and Semiarid Resource-based Urban Agglomerations

With the rapid development of urban agglomerations in northwest arid and semiarid regions of China, the scope of the urban heat island(UHI) effect has gradually expanded and gradually connected, and has formed a regional heat island(RHI) with a larger range of impact to the regional environment. However, there are few studies on the heat island effect of urban agglomerations in arid and semiarid regions, so this paper selects the urban agglomeration of Hohhot, Baotou and Ordos(HBO) of Inner Mongolia, China as the study area. Based on the 8-day composite Moderate-resolution Imaging Spectroradiometer(MODIS) surface temperature data(156scenes in all) and land use maps for 2005, 2010, and 2015, we analyze the spatiotemporal distributions of regional heat(cool) islands(RH(C)I) and the responses of surface temperatures to land-use changes in the diurnal and interannual surface cities. The results showed that: 1) from 2005 to 2015, urban areas showed the cold island effect during the day, with the area of the cold island showing a shrinking feature;at night, they showed the heat island effect, with the area of the heat island showing a first decrease and then an increase.2) From 2005 to 2015, the land development(unutilized land to building land) brings the greatest temperature increase(ΔT = 1.36°C)during the day, while the greatest temperature change at night corresponds to the conversion of cultivated land to building land(ΔT =0.78°C) exhibited the largest changes at night. From 2010 to 2015, the land development(grassland to building land) bring the greatest temperature increase(ΔT = 0.85°C) during the day, while the great temperature change at night corresponds to the conversion of water areas to building land(ΔT = 1.38°C) exhibited the largest changes at night. Exploring the spatial and temporal evolution of surface urban heat(cool) islands in urban agglomerations in arid and semiarid regions will help to understand the urbanization characteristics of urban agglomerations and provide a reference for the formulation of policies for the coordinated and healthy development of the region and co-governance of regional environmental problems.

Spatiotemporal Variations and Regional Transport of Air Pollutants in Two Urban Agglomerations in Northeast China Plain

Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to 2017.The results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern region.Megacities such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in China.The annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing trend.All the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological conditions.PM2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind conditions.High O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are strong.Regional transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.

Impact of Anthropogenic Aerosols on Summer Precipitation in the Beijing–Tianjin–Hebei Urban Agglomeration in China:Regional Climate Modeling Using WRF-Chem

The WRF model with chemistry （WRF-Chem） was employed to simulate the impacts of anthropogenic aerosols on summer precipitation over the Beijing-Tianjin-Hebei urban agglomeration in China. With the aid of a high-resolution gridded inventory of anthropogenic emissions of trace gases and aerosols, we conducted relatively long-term regional simulations, considering direct, semi-direct and indirect effects of the aerosols. Comparing the results of sensitivity experiments with and without emissions, it was found that anthropogenic aerosols tended to enhance summer precipitation over the metropolitan areas. Domain-averaged rainfall was increased throughout the day, except for the time around noon. Aerosols shifted the precipitation probability distribution from light or moderate to extreme rain. Further analysis showed that the anthropogenic aerosol radiative forcing had a cooling effect at the land surface, but a warming effect in the atmosphere. However, enhanced convective strength and updrafts accompanied by water vapor increases and cyclone-like wind shear anomalies were found in the urban areas. These responses may originate from cloud microphysical effects of aerosols on convection, which were identified as the primary cause for the summer rainfall enhancement.

Measurement of Urban Economic Gravity of China’s Three Major Agglomerations and Its Implications for the Coordinated Development of the Beijing-Tianjin-Hebei Region

This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerations,including the Beijing-Tianjin-Hebei region,the Yangtze River Delta,and the Pearl River Delta.The results show that,despite the ever-tightening economic linkages among cities in the urban agglomerations,the development of the Beijing-Tianjin-Hebei region falls behind that of the Yangtze River Delta and the Pearl River Delta in terms of coordination,closeness,and balance.The economic linkages among cities in the Beijing-Tianjin-Hebei region are not as cohesive as they could be and display a significant“siphon effect”through Beijing and Tianjin as well as a prominently unidirectional economic flow.This study suggests that efforts should be put into directing the orderly flow of resources from Beijing and Tianjin to cities in Hebei and promoting a balanced economic flow among cities,thus facilitating the coordination of regional development.

Impact of Anthropogenic Heat Release on Regional Climate in Three Vast Urban Agglomerations in China

We simulated the impact of anthropogenic heat release （AHR） on the regional climate in three vast city agglomerations in China using the Weather Research and Forecasting model with nested high-resolution modeling.Based on energy consumption and high-quality land use data,we designed two scenarios to represent no-AHR and current-AHR conditions.By comparing the results of the two numerical experiments,changes of surface air temperature and precipitation due to AHR were quantified and analyzed.We concluded that AHR increases the temperature in these urbanized areas by about 0.5℃-1℃,and this increase is more pronounced in winter than in other seasons.The inclusion of AHR enhances the convergence of water vapor over urbanized areas.Together with the warming of the lower troposphere and the enhancement of ascending motions caused by AHR,the average convective available potential energy in urbanized areas is increased.Rainfall amounts in summer over urbanized areas are likely to increase and regional precipitation patterns to be altered to some extent.

Dynamic Evaluation on Regional Tourism Competitiveness:Urban Agglomeration of Shandong Peninsula,Eastern China

The article establishes the appraisal index system for entire urban agglomeration and its interior cities individually,concretely including five aspects:driving forces for tourism development,the level of tourism development,tourism impacts,tourism economic connection and tourism contributions of different cities to the whole urban agglomeration.As tourism competitiveness has the characteristics of comprehensiveness,systematicness and dynamicness,the article attempts to apply the structural prediction means of system dynamics to evaluating tourism competitiveness,aiming to provide some research methods and analysis ideas for tourism competitiveness measurement and trends analysis in urban agglomeration.Taking Shandong Peninsula urban agglomeration as the study area,the article simulates and analyzes the tourism competitiveness trend of the whole region and its interior cities from 2005 to 2020,and the result reflects that integrated development and regional combination of tourism are important means to upgrade tourism competitiveness in this region.

Impact of Climate Change on Urban Agglomerations in China’s Coastal Region

Climate change and urbanization issues are the two key factors that make humans liable to be affected by disasters, which are overlapped in urban agglomeration. The five big urban agglomerations of China with strong economic power are the important engines for national economic and social development. However, being in the sea-land mutual interaction belts with a vast hazard-bearing body, they are affected by sea-land compound disasters, and are liable to suffer heavy disaster losses with climate change. It is suggested that government departments concerned should fully recognize the impact of climate change on coastal urban agglomerations, propose strategies as soon as possible, and integrate the impact of climate change and adaptation countermeasures into the various kinds of social-economic development plans for coastal urban regions.

FORMATION MECHANISM AND SPATIAL PATTERN OF URBAN AGGLOMERATION IN CENTRAL JILIN OF CHINA

Urban agglomeration is made up of cities with different sizes to be linked by traffic network in a given area, and it is an inevitable result when urbanization reaches a certain level. Taking urban agglomeration in central Jilin (UACJ) as an example, this article analyzes the formation mechanism and spatial pattern of urban agglomeration in the less-developed area. First, the dynamics of UACJ has been analyzed from the aspects of geographical condition, economic foundation, policy background, and traffic condition. Then the development process is divided into three stages-single city, city group and city cluster. Secondly, the central cities are identified from the aspects of city cen- trality, and the development axes are classified based on economic communication capacity. Finally, the urban agglo- meration is divided into five urban economic regions in order to establish the reasonable distribution of industries.

Agglomeration Shadows amid China’s Urbanization:From a High-Speed Railway Perspective

Using China’s county-level panel data of 2007-2016,this paper verifies the existence of agglomeration shadows from an infrastructure development perspective.With high-speed railway(HSR)launch as a quasi-natural experiment,we find that the launch of HSR lines was followed by a decrease in GDP per capita of counties along the route by 2.6 percentage points.This conclusion remains valid after a series of robustness tests and the treatment of potential endogeneity problem.Mechanism analysis suggests that such effect is the most significant for counties within a distance of 97 to 195 km to the nearest central city,which is a manifestation of the“agglomeration shadows.”We also uncover that HSR would spur economic growth for counties with favorable endowments.However,HSR also has a significant negative impact on permanent population in counties.When change in permanent population is taken into account,HSR’s negative impact on the countywide economy becomes smaller.Shrinking permanent population in counties after HSR launch is a manifestation of such agglomeration shadows.HSR has facilitated the free flow of population.These findings point to the possibility that HSR may have induced regional economic equilibrium amid agglomeration.

京津冀协同发展战略实施十年回顾及展望

京津冀协同发展战略实施近十年来,北京非首都功能疏解取得明显成效,北京城市副中心和雄安新区“两翼”建设稳步推进,三地交通一体化、生态联防联控、产业转型升级三大领域取得率先突破,区域内体制机制改革与创新稳步实施。但仍面临经济份额下降、创新驱动经济增长能力不强、人口和经济过密与过疏现象并存等问题。展望未来,应从现代化首都都市圈建设、打造“一核两翼”空间新格局、优化区域现代产业分工体系与区域创新格局、创新跨区域协同治理体制机制等方面,全面推进京津冀协同发展迈向更高水平、更优效益和更高质量,努力使京津冀成为中国式现代化建设的先行区、示范区。

城市群人口集聚对共同富裕的影响——基于粤港澳大湾区的分析

共同富裕是中国式现代化的重要特征和中国特色社会主义的本质要求,如何推进共同富裕目标的实现成为政府和学界亟待解决的难题。以粤港澳大湾区为样本探讨城市群人口集聚对城市群内部以及周边区域共同富裕的影响,在理论分析的基础上采用“全面FGLS”方法以及动态面板空间杜宾模型进行估计得到如下结论:粤港澳大湾区人口集聚无论是对于城市群内部共同富裕还是带动周边区域共同富裕均具有积极的促进作用,在短期内存在正向的空间溢出作用,但长期而言粤港澳大湾区人口不可能无限集聚,当发展到一定程度后拥挤效应将超过集聚效应对共同富裕产生负面影响。上述结论意味着当前粤港澳大湾区内部形成的多中心集聚的态势,空间协调发展程度较高,在推动城市群内部共同富裕的同时,短期内也带动了周边区域的发展,但长期持续的发展仍需人口在粤港澳全域更为均衡地分布,而非无限向粤港澳大湾区集聚。基于上述结论,提出应重视基础设施的互联互通、产业互联、城市互联等,促进粤港澳大湾区与粤东西两翼及山区人口等要素资源更为顺畅地流动,优化资源配置,促进粤港澳全域发展,实现真正意义上的先富带动后富,最终实现共同富裕。

长三角城市群物流业高质量发展水平测度研究及评价

以长三角城市群物流业为研究对象,采用熵权TOPSIS法和核密度估计分析方法,测度2010—2021年长三角城市群物流业高质量发展水平并分析区域发展差异。研究发现:长三角城市群物流业高质量发展水平向好趋势明显,但仍然有待提高。有18个城市的物流业高质量发展水平低于均值。其中上海的物流业高质量发展水平最高,居于第2位的苏州相比于上海还有较大差距。从各区域来看,区域发展不均衡的特征较明显,各区域物流业高质量发展水平存在一定差距,上海物流业高质量发展水平显著高于其他区域,物流业高质量发展水平排名靠后的城市主要集中在安徽,该区域内发展差距呈现缩小趋势。

我国五大城市群县域科技创新效率空间分异与障碍因子分析

城市群作为创新要素集聚地,在全国生产力布局中发挥战略性支撑作用,县域是城市群协同创新的重要空间载体,在中国未来城市发展中拥有不可或缺的重要地位。采用DEA-BCC效率模型、核密度、空间探索性等研究方法,测算2018—2021年长三角、珠三角、中原、成渝以及长江中游城市群所辖县域科技创新效率,并采用障碍度模型识别影响五大城市群县域创新效率的主要因素。结果表明:五大城市群县域科技创新效率存在较大差距,其中,高新技术产业发展、创新平台建设、企业创新投入和科技人力资源禀赋等是阻碍县域科技创新效率提升的重要因素,进而提出城市群县域科技创新效率优化路径。

逆全球化背景下区域协同创新网络抗毁性评价——以长江经济带城市群为例

从结构抗毁性和功能抗毁性两个维度构建区域协同创新网络抗毁性评价指标体系,进而提出改进的AHPCRITIC组合赋权法确定指标权重,并采用TOPSIS方法对长江经济带3个城市群协同创新网络的抗毁性水平进行综合评价。结果表明,长三角城市群的协同创新网络抗毁性水平最强,成渝城市群次之,中游城市群最低;随着时间推移,长三角城市群的抗毁性持续增强,成渝城市群呈现“V”型减弱趋势,中游城市群呈现“V”型增强趋势;从结构抗毁性看,长三角城市群持续增强,成渝城市群与中游城市群呈现“V”型增强趋势但增幅较小;从功能抗毁性看,长三角城市群与中游城市群均呈现“V”型增强趋势,而成渝城市群呈现“V”型减弱趋势。

基于城镇要素集聚能力视角的重庆市区域发展空间分异研究

为了揭示重庆市38个区县在2005—2019年间区域发展空间分异情况,本研究基于城镇要素集聚能力指数,结合崔王指数、障碍度评价法展开实证分析。结果表明:(1)区域发展水平整体呈螺旋式上升趋势,空间上呈现出明显的核心(主城区)—外围(非主城区)结构特征,但分异程度在不断下降。(2)非农产业产值、人均GDP、非农就业人数、年末金融机构贷款余额、公共财政预算收入、空间规模以上企业总产值等因子是导致重庆市38个区县城镇要素集聚能力空间分异的关键性因子,其作用机理与重庆市地形区位、要素流动可达性和贫困区县空间分布所形成的“发展势能”的空间分异密切相关。(3)为了实现要素自由流动和区域协调发展,提出进一步强化主城区的核心集聚能力和扩散带动作用、弱化地形对空间相互作用的影响、构建“一圈两翼、一主两副”空间结构、深化“走出去、引进来”对外开放战略、强化(科技、体制机制、人才等)创新和生态文明建设引领作用等的对策建议。研究表明源于城镇要素集聚能力的区域发展空间分异研究方法,可以形象地将要素移动呈现在“发展势能”和要素移动成本的变化曲线中,对于深挖区域发展空间分异的主要影响因素及其形成机理具有较强的解释力;重庆市可以从区域城镇要素低成本自由流动、核心对外围辐射带动作用层面构建区域协调发展实现路径。

新质生产力对区域经济韧性的影响研究

发展新质生产力、增强区域经济韧性,是推动区域经济高质量发展、加快塑造发展新动能新优势的重要途径。本文基于2010~2022年我国31个省(区、市)面板数据,在测度新质生产力和区域经济韧性的基础上,实证检验新质生产力对区域经济韧性的影响。研究发现,新质生产力可对区域经济韧性产生正向促进作用。异质性结果表明,新质生产力对区域经济韧性的促进作用会受到区域经济发展水平以及城市群层级的影响,对经济欠发达地区、非五大城市群区域的经济韧性产生的正向促进作用更强。因此,应结合区域资源禀赋差异加快发展新质生产力,不断增强区域经济发展韧性,为推动区域经济高质量发展、推进中国式现代化的地方实践探索差异化路径。

因地制宜发展新质生产力的现实依据与实施路径--来自西部地区九大城市群的经验证据

党的二十届三中全会通过决定--《中共中央关于进一步全面深化改革推进中国式现代化的决定》,强调要健全因地制宜发展新质生产力体制机制。作为新形势下中国经济实现高质量发展的重大部署和重要抓手,发展新质生产力绝不能出现各地区一哄而上、产业雷同和恶性竞争的局面,相反,需要结合地方自然资源禀赋、地理生态环境、人口教育水平、数字基础设施、创新研发能力等因素探寻比较优势和合适路径。西部地区作为国家安全与长远发展的重要基础,在中国式现代化进程中发展相对滞后,影响着中国经济高质量发展的总体水平。成渝、呼包鄂榆、北部湾、关中、滇中、兰西、宁夏沿黄、黔中和天山北坡等九大城市群是我国西部地区发展的重要动力源,也是西部地区抢抓新质生产力发展机遇的高地。文章基于2012—2022年中国西部地区城市面板数据,从科技生产力、绿色生产力和数字生产力三个维度构建综合评价指标体系,采用熵值法测算西部地区九大城市群新质生产力发展水平及各维度指数得分,并运用Dagum基尼系数法、核密度估计法、马尔科夫转移概率矩阵、σ收敛模型和β收敛模型考察了西部地区城市群新质生产力发展水平的时空特征、差异来源、演进规律及收敛机制。研究发现,整体而言西部地区城市群新质生产力发展水平呈现逐年增长态势,但总体水平偏低且表现出明显的梯度差异;并且存在着科技生产力水平最高、数字生产力水平次之、绿色生产力水平居末位的结构分解特征。在相对差异方面,西部城市群新质生产力发展水平的总体差异较为显著,其中超变密度和区域间差异是城市群区域差异的主要来源。在绝对差异方面,西部城市群的新质生产力发展水平的空间差异具有进一步扩大的趋势,并且存在“俱乐部趋同”现象和一定程度的“马太效应”。在收敛特征方面,短期来看西部地区的新质生产力水平差距尚未缩小,但长期来看存在绝对β收敛和条件β收敛趋势,即西部城市群新质生产力水平将在长期收敛到稳态水平。因此,西部地区在培育和发展新质生产力的进程中,既要因地制宜挖掘特色优势,又要统筹合作推进协调发展。

Policy spillover and regional linkage characteristics of the real estate market in China's urban agglomerations

The main purpose of this study is to determine the spillover effect of real estate regulatory policies released by core cities on the surrounding cities in major urban agglomerations based on regional linkage characteristics of China's real estate market.In this study,real estate transaction data of 157 cities were selected from 11 major urban agglomerations.Agglomeration's housing transaction volatility and spillover effect caused by the core city's regulatory policies were simulated by integrating spatial and temporal analysis model,event analysis,and symbolic time series analysis.The findings showed that(1)the regional linkage of the real estate market in the Harbin-Changchun and Middle-South Liaoning,Middle Reaches of the Yangtze River,Yangtze River Delta,Pearl River Delta,and West Side of the Straits agglomerations were remarkably tight and the core cities'policy spillover effect was significant,of which the house purchase limitation and credit limitation policies had the widest influence;(2)the regional linkage of the real estate market in the Beijing-Tianjin-Hebei agglomeration,Shandong Peninsula,Guanzhong Plain,and Chengdu-Chongqing agglomerations was relatively weaker,but the core cities'policies of mar-ket regulation and taxation had certain spillover effect;(3)there were significant differ-ences in the spillover effects of different types of policies in different urban agglomerations;(4)generally,the core cities'policy spillover often reduced the changing characteristics of the real estate market and made it more ordered with more certainty in the whole agglomeration,with the exception of the Beijing-Tianjin-Hebei,West Side of the Straits,and Chengdu-Chongqing agglomerations.